This invention relates to a door-to-door transit system which primarily utilizes privately-owned vehicles to provide high-volume, low-cost, energy-efficient and ecologically-sound transportation services for the public, including the aged and the handicapped.
In view of the critical transportation, environmental and energy problems now facing the world, new approaches are constantly being sought to reduce the dependence upon single-passenger automobile trips for transportation. Unfortunately, attempts to eliminate the single-passenger auto have met with only limited success to date. Consequently, gasoline consumption, traffic congestion and air pollution levels remain high.
Although great emphasis has been placed on mass transit systems to alleviate these problems, mass transit systems are extremely costly to build and operate. Bus systems require large outlays for vehicles and operating personnel, while fixed-guideway systems require capital expenditures many times greater than those required for bus systems. Equally important, the fact that both high-volume bus systems and fixed-guideway systems must adhere to predetermined routes, makes it impossible for such systems to provide door-to-door service for most citizens.
Door-to-door transportation service is a requirement for many aged and handicapped persons. Door-to-door service is also desirable for other riders, since the time and energy required to get riders to and from transit stations reduces both the convenience and the energy efficiency of mass transit systems. Although taxis, jitneys and dial-a-ride minibuses offer door-to-door convenience, the necessity of having a driver who makes his living providing such service to relatively few riders renders it far too expensive for most citizens to use on a regular basis. Hitchhiking is too dangerous to consider as a viable transportation system.
Although one of the least energy efficient forms of transportation is an automobile with a single occupant, one of the most energy efficient forms is an automobile with several occupants. Car pools, van pools and other ridesharing programs have been encouraged to reduce petroleum consumption while providing riders with economical, door-to-door transportation services. The advantages of ridesharing are well-known. By increasing the average number of passengers in each vehicle, the number of vehicle-miles can be reduced while keeping the number of passenger-miles constant. By sharing the operating costs both the rider and the driver save money, while gasoline consumption, parking, traffic congestion and air pollution problems are all reduced.
Despite these benefits and an intensive advertising campaign, 75% of all workers who commute by automobile drive by themselves. One of the reasons for this is the absence of suitable backup transportation for commuters who rideshare, such backup transportation being needed whenever a driver's or a rider's itinerary changes. Because noncommuter travel is less regular and repetitive than commuter travel, conventional ridesharing techniques have been used even less for this type of travel. Noncommuter travel currently represents 60% of all automobile trips.
Our existing automobiles and roads constitute an effective door-to-door transportation system for many citizens. Because of the low occupancy rate of the vehicles, however, it is a very inefficient system. Furthermore, the system is not always responsive to the needs of those who either cannot afford an automobile or cannot drive. What is required is a method for using the existing inventory of empty auto seats on our highways to respond to the transportation demands of the general public, including the aged and the handicapped, on an individual trip basis. Voice systems, currently used by radio-dispatched taxi and dial-a-ride minibus services, are too slow and too labor-intensive to be used for high-volume transportation systems. The volume of information to be processed and the time constraints mandate that such a door-to-door, demand-responsive system be automated in all but the smallest towns.
In recent years a number of automated, demand-responsive mass transit systems have been developed with a view toward increasing their efficiency and cutting their cost of operation. Among these are the systems shown in the following U.S. Pat. Nos.: 3,268,727, 4,023,753, 3,895,584, 4,092,718, 3,953,714, 4,181,945, 4,015,804, 4,208,717. Also of interest is Bennett et al, IBM Technical Disclosure Bulletin, Volume 14, No. 2, pages 438-440 (July 1971). Most of these systems apply to fixed-guideway mass transit systems, although U.S. Pat. No. 4,092,718 and the IBM Technical Disclosure Bulletin pertain to bus systems. In every case, however, the mass transit system involves vehicles traveling along predetermined routes between predetermined stations. That is, each vehicle in the system has respective origins and destinations which bear a predetermined route relationship to one another. The stations do not vary according to current rider needs. Accordingly, these systems share the major disadvantages of other mass transit systems in their high capital costs and inability to provide door-to-door transportation.
Unfortunately such automated, demand-responsive transportation systems of the fixed-route, station-to-station type are not easily adapted to a flexible-route system because of the many unique problems presented by door-to-door service. In order to be effective, a high-volume door-to-door system requires many more vehicles of smaller seating capacity than a station-to-station system. A door-to-door system must also be able to instantaneously match a large number of different ride requests with an equally large number of different ride offers. Common routing is not the only criterion for effective matching. Timing and seating needs of riders require matching with timing and seating capacities of vehicles.
Because of the volume and complexity of the data required in a trip-by-trip scheduling system, special computer terminals should be used to permit both drivers and riders to enter trip information quickly and accurately and transmit this information to a computer for driver-rider matching. This matching must be accomplished on a real-time basis in response to current demands, and without the need for human intervention.
In order to minimize capital costs, most of the transit vehicles should be privately owned. In order to minimize operating costs, extensive use should be made of volunteer and part-time drivers, particularly during peak traffic periods. The security of private citizens who do not know each other but nonetheless share rides with each other must be ensured. The current suitability, from a point of view of safety and liability, of private vehicles and their drivers to transport riders must be monitored continuously. Furthermore once a vehicle is assigned to a rider or group of riders, some method must be provided to ensure that vehicles and riders will make proper connections. The ability to deal with all of these variables on an instantaneous, real-time basis is far beyond the capability of known fixed-route automated transportation systems.